1. Field of the Invention
The present invention relates to an attachment structure for drive cables of a robot, and a robot apparatus provided with the attachment structure.
2. Description of the Related Art
In order to operate a multiple-joint robot as intended, it is necessary for the robot to be provided with power cables for supplying necessary power to a servo motor disposed at each joint, signal cables for transmitting and receiving signals to and from the servo motors or detectors which detect rotary movement of the servo-motors, and the like. It is preferable that drive cables installed on a robot (in the present specification, various cables necessary for operation and control of robot are hereinafter referred to as “drive cables”) have an extra length so that excessive force can be prevented from exerting on the drive cables when the respective joints are in rotational movement. On the other hand, the drive cables with an extra length may sometimes have excessive slack, depending on the position and posture of the robot. Therefore, it is preferable that the drive cables are configured so as not to interfere with peripheral objects such as a hand, jig, workpiece, and other robots.
JP-A-2005-14159 discloses an attachment structure for cables of a robot. The attachment structure includes a hollow support structure on which the robot is placed, and the cables can be fixed and connected to a wiring connection in the interior of the support structure. According to another related art, an attachment structure has a configuration in which drive cables are wound around a cylindrical support structure. According to yet another related art, an attachment structure has a configuration in which a fixing member is provided to fix drive cables at a position away from a support structure of a robot to the rear.
However, in the attachment structure disclosed in JP-A-2005-14159, the drive cables cannot be easily introduced into the interior of the support structure, and therefore, the assembly and maintenance of the robot become complicated. Moreover, since a space is required to accommodate the extra length parts of the drive cables, the size of the support structure is increased. Furthermore, if the space requirements for the interior of the support structure are severe, it is necessary to specifically determine the length of the extra length parts of the drive cables, the direction in which the extra length parts extend, or the like, in order to prevent the drive cables from coming in contact with the support structure, which may result in damaging the drive cables, when the robot is in operation.
In the attachment structure configured by winding the drive cables around the support structure, a protection member is required in order to prevent the drive cables from coming in contact with the support structure, a cover attached to the support structure or the like, which may result in damaging the drive cables. In addition, in the attachment structure including the fixing member situated behind the support structure of the robot, a projecting part projecting in the space behind the robot becomes large, which increases the entire size of the robot apparatus.
Accordingly, there is a need for an attachment structure for drive cables of a robot, which is easy to handle and enhances working efficiency.